Hey guys im new here, looking for some advice on my transmission issue. I have a 2003 silverado 2500hd 4wd with a 6.0 liter that has about 200k.
Symptoms- If I rev it in park it makes a grinding noise sounds like it wants to engage and move, if i put it in drive it doesnt want to move(truck has been a plow truck) any help is greatly appreciated
Thanks

 

sounds like sun gear and planitary are shot. also maybe snapped the input shaft

 

Rebuild time. Sounds like the Torque Converter has seen it's better days. If your still going to use it as a plow truck, definitely spend the extra bucks on a beefed up Converter and replace the pump- because even though it may look good, plowing has probably got it close to melt down a couple of times and your rebuild will last and perform great.